1. Technical Field
The disclosure generally relates to proximity sensor modules, particularly to a capacitive proximity sensor module and an electronic device using the capacitive proximity sensor module.
2. Description of Related Art
Proximity sensors are built into many electronic devices (e.g., tablet computers) to detect when an external object, such as a human body part, comes within a given distance of the electronic device. When the presence of an external object in a vicinity of the electronic device is detected, a transmit power of an antenna of the electronic device may be reduced to ensure that radiation transmission levels are sufficiently low to meet regulatory limits for specific absorption rate (SAR). When the external object is no longer present, transmit power of the antenna may be increased. Generally, a typical capacitive proximity sensor includes a detecting circuit and a sensing element which can be a sensing capacitor or a group of sensing capacitors. Capacitance of the sensing element changes according to the presence or absence of the conductive or the dielectric object in the vicinity of the sensing element. The detecting circuit detects capacitance changes of the conductive or the dielectric object, and transmits signals accordingly.
A typical sensing element of the capacitive proximity sensor is made of copper and formed on a printed circuit board (PCB) of the electronic device. However, the sensing element occupies area of the PCB which causes an increase in overall volume of the electronic device.
Therefore, there is room for improvement within the art.